“It pissed me off”

It HAS to be sustainable for you. That’s the secret of weight loss. Whatever you do that causes you to lose weight, you do forever. That’s why most diets fail.

I run ultras, play ice hockey, lift heavy, but I do so without carbs. (I eat around 20g per day.) If I want to be explosive (like sprinting), I do need carbs, but having your body burn fat vs glycogen (carbs) is perfect for long distance running.